Sunday, October 18, 2015

Living and working in greater Chicagoland, and chairing this year’s Summit Planning Committee… I have put a lot of thought into my own recommendations for what are some “must do” tourist things for attendees who have a bit of free time (either before or after the event) in addition to participating in everything during the Summit that has already been planned for them. In no particular order here are the top 11 that came to mind:

1. Millennium Park – It’s beautiful and directly across the street from the Hotel. Head north just a bit to hit Cloud Gate (aka “The Bean”). Simply put – you don’t get credit for having seen Chicago without having your photo taken with “The Bean”. And if you have kids with you and/or are considering coming back with kids… head over the really cool bridge to check out Maggie Daley Park... perhaps the coolest children’s playground I have ever seen.2. Garrett Popcorn – Right there with “The Bean” is Garrett Popcorn. You have to get the “Chicago Mix”, and, yes, it’s addictive. Also, it doesn’t save well… so if you plan on bringing it home as a gift (which is a great idea), make sure you get it the day you are leaving and/or purchase it at O’Hare (assuming that’s the airport you are leaving from). 3. Willis (Sears) Tower Skydeck – Not only does the Skydeck, which is easily walking distance from the Hilton, provide the absolute best views of Chicago at 103 floors up… but you can walk out on a ledge and look straight down. And… for those power transmission junkies out there (should be anyone reading this blog post)… be sure to also look up when you are standing on the ledge. You will see that the ledge is actually hung on rails (to allow the ledges to pull back for window washing systems)… and, if you look carefully enough, you should be able to spot a few familiar orange label couplings above your head. 4. Chicago Cubs Playoff Games – While I certainly can’t advocate blowing off the Welcome Reception on Thursday night (assuming the series goes to 5 games)… if you are in town Tuesday or Wednesday night and don’t mind cashing in your entire retirement account to get tickets… yes, the Chicago Cubs are in town in pursuit of the National League title. And, for those of you who value your retirement savings… the excitement and energy in Chicago is currently off the charts. Go find a local bar to watch the game at and celebrate with the locals. While there order a Chicago style hot dog (don’t make the mistake of putting ketchup on it!) or an Italian Beef sandwich.5. Chicago Deep Dish – Everyone has their favorite and their own opinion… but if it were up to me, I’d recommend walking or taking a cab north up Michigan Avenue to the original Pizzeria Uno (or their sister location across the street, Pizzeria Duo) at 29 E Ohio Street. Of course, Chicago has some of the world’s finest restaurants of all varieties (from Rick Bayless’s Mexican restaurants to Giuliana & Bill Rancic’s RPM Italian to too many world class steak houses to count)… so, if you want to go a bit more upscale, I certainly won’t hold it against you.

6. Architecture Boat Tour – Chicago is certainly known for its skyscrapers, and there is no better way to learn about them than from one of Chicago’s many fantastic boat tours. While there are many to choose from that are excellent… the Chicago Architecture Foundation’s is one of the most respected.

7. The Art Institute of Chicago – Directly across the street from the Hilton and just a bit north, this museum has an unbelievable breadth and depth of exhibits to enjoy. While I believe they certainly had to have done some heavy lobbying, one of the museums many claims to fame was that it was rated the “#1 Museum in the World” by Trip Advisor last year.

8. Museum Campus Chicago – Whether you would like to check out one the world’s finest natural history museums (the Field Museum - which includes Sue the T-Rex), one of the world’s finest aquariums (the Shedd Aquarium), or planetariums (Adler Planetarium)… they are all a short walk (or cab ride) south east of the Hilton.

9. Michigan Avenue Shopping – From the Hilton, head north up Michigan Avenue and across the river… and you will soon find yourself surrounded by some of the biggest (and priciest) retail shopping anywhere. And if you find you need a quick bite in the midst of blowing your retirement savings (assuming you didn’t already blow it on the Cubs game)… the foodlife food court in Water Tower Place (835 N Michigan Avenue) is out of this world cool.

10. Chicago Blackhawks & Bulls Games – I listed this last because the United Center is a bit far away from the hotel, home games are generally at inopportune times, and both teams are very early in the season. If nothing else, these teams will provide something fun to watch while socializing with other PTDA members at the bar. Getting to the details now… the Blackhawks have home games on Thursday night (which nobody better go to because it is the same time as the PTDA Industry Summit Welcome Reception) and Saturday night (which nobody better go to because it is the same time as the PTDA Industry Summit Speakeasy closing event). The Bulls have pre-season home games on Tuesday (open if you get into town early) and Friday night (overlaps offsite hospitalities/dine-arounds). And if you are wondering about the Chicago Bears... they've got an off week.11. PTDA Office Tour - For those who may not be aware, PTDA is headquartered in Chicago, just over a mile away from the Hilton at 230 W. Monroe Street. Now the PTDA staff is going to be more than busy running the Industry Summit during the event itself, but if you are in town either before or after... it might not be a bad idea to call and ask to see the actual physical location of your organization. (Note: The PTDA offices are in a skyscraper building with security, so you will need to coordinate your visit with PTDA staff in advance should you wish to visit.)

So that's my first cut at a list. What other big "must do" things did I miss? If you've got one, please let me know in the comments below. Looking forward to seeing everyone in just a few days!

Thursday, October 1, 2015

If history is any judge, this post will be by far the most popular in our mini-series of three blogs on disc couplings. The first post provided a broad overview of disc couplings, and the second posts covered a number of key terms used when talking about disc couplings... but this third post is on the riveting topic of disc coupling failures.

To date, the Coupling Answers blog posts coupling failures (including Jaw Coupling Failure Analysis , Gear Coupling Failure Analysis, and Grid Coupling Failure Analysis) have been extremely well-received and appreciated by our amazing customer base. One of the reasons these posts have been so well received is that so few people like to talk about failures. Fortunately, we at Lovejoy, are confident enough in our products, design capabilities, and general understanding of power transmission that troubleshooting isn't something we shy away from. (In fact, for Hannover Fair 2015, we actually hosted a Coupling Solutions Learning Lab that was loaded with actual failed couplings. This caught countless German engineers completely off-guard.) Moving on...

Misalignment Failures

Misalignment Failure

Like many other coupling types, disc couplings often fail in with telling or "signature" ways that point to a likely culprit. As pictured at right, when a disc coupling is subject to excessive misalignment it is likely to experience disc pack cracking near the bushings, with the outer layers fracturing first.

Misalignment Failure

Note: Given disc packs generally crack from the outer layers in, it is certainly possible that a coupling will continue to transmit torque/function with cracks in the outside layers. This means that it is still important to inspect the disc pack on a periodic basis even if the coupling appears to be functioning properly. Fortunately disc packs can generally be inspected without disassembling the coupling, and possibly even when the coupling is running (by using a strobe light assuming the coupling guard is not solid steel).

If misalignment is the likely source of a disc pack failure, it is important to realign the coupling prior to restarting the system, less the issue repeat itself. (Two options to consider when realigning a coupling are laser alignment and dial indicators.) An additional step you can take if you are not using a scalloped disc pack by Lovejoy (which offers increased misalignment handling over legacy designs), you can source a replacement coupling from us!

Misalignment Failure

Torque Overload Failures

Disc Pack Torque Overload Failure

Torque overload failures in disc packs look different from misalignment failures in that the fatigue cracks tend to form in the center of the disc pack rather than up against the bushings (as pictured at right).

A second thing to look for when suspecting torque overload on this disc pack is any evidence that the disc pack layers (or laminates) are separating or ballooning away from each other in the center sections between bushings.

Bent Disc Pack Bolts

In addition to the disc packs themselves, the bolts used to connect the disc pack to the flanges may be bent or distorted. Such distortions are another excellent indication that the coupling is seeing torque in excess of what it was designed to handle.

Disc Coupling Hub Burst

A third and final common way that torque overload reveals itself in a disc coupling is if a coupling hub actually bursts over the corner of the keyway. This is a failure mode common across many coupling types, and the reason the coupling fails at this point is because, due to the cut keyway, this is the weakest point in the hub.

Installation & Fastener Failures

One of the fastest way to damage a disc coupling during installation is to use impact wrenches. (Do not do this!) Not only does using an impact wrench raise the potential of twisting the disc pack (pictured at right) in a destructive manner, but it also raises the possibility of friction welding the fastener bolts to either the disc pack and or the connected flange. Fasteners should be lubricated prior to installation and torqued with care.

On the other end of the spectrum, improper torque of the fasteners may cause them to loosen. This loosening can then lead to damage and wear to the fasteners as well as hole elongation and cracking of the disc packs. To avoid either over or under torquing the fasteners, be sure to read and follow the disc coupling's installation instructions. (Lovejoy's disc coupling installation instructions and videos can be found here.)

Environmental Failures

While disc couplings generally hold up very well to many environmental conditions, they are certainly not impervious to everything. As such, it is critical that coupling users understand what corrosive agents may be present for a given application, and that the disc coupling is designed to operate under those conditions. (Pictured at right is a circular, non-scalloped, disc pack layer that has been corroded.)

Life Expectancy

Having just covered misalignment, torque overload, installation, fastener, and environmental failures of disc couplings, a natural question might be "How long is my coupling going to last?" Unfortunately, like all other coupling type, disc coupling life is not generically predictable as it is highly dependent upon the application and the misalignment of the given system it is driving. Shaft alignment does correlate strongly with longer coupling life... so taking the time to align the system properly with periodic checks should pay lasting dividends and not be overlooked.